Stdio integration tests: increase initialize timeout to 25s

The initialize timeout was too short to be able to download the server
with NPX. As stated in the javadoc of `StdioMcpSyncClientTests`:

> These tests use npx to download and run the MCP "everything" server
> locally. The first test execution will download the everything server
> scripts and cache them locally, which can take more than 15 seconds.
> Subsequent test runs will use the cached version and execute faster.

Since the download happens on calling "connect", it is triggered during
the initialization of the client.

Signed-off-by: Daniel Garnier-Moiroux <git@garnier.wf>

mcp-test/src/test/java/io/modelcontextprotocol/client/StdioMcpSyncClientTests.java

@@ -67,7 +67,7 @@ class StdioMcpSyncClientTests extends AbstractMcpSyncClientTests {
 	}
 
 	protected Duration getInitializationTimeout() {
-		return Duration.ofSeconds(10);
+		return Duration.ofSeconds(25);
 	}
 
 	@Override